1. Technical Field
The present invention relates to an electrooptical device, an electronic device using the same, a control method for an electrooptical device, and the like.
2. Related Art
An electrophoretic display device is known as one example of an electrooptical device. An electrophoretic display device is configured such that electrophoretic elements including pigmented electrophoretic particles are held between a pixel electrode and an counter electrode. The electrophoretic display device displays an image by causing the electrophoretic particles to migrate through application of a voltage between these two electrodes. At this time, in the electrophoretic display device, the color of the displayed image can be changed by, for example, controlling the electrophoretic particles pigmented in different colors to migrate independently on a per-color basis. The electrophoretic elements are composed of, for example, a plurality of microcapsules that are sealed between the pixel electrode and the counter electrode. Every microcapsule includes a plurality of electrophoretic particles.
Technology related to such an electrophoretic display device is disclosed in, for instance, the following examples of related art: JP-A-2000-194021, the specification of US-A1-2011/0310461, the specification of US-A1-2006/0202949, T. Yashiro, “Novel Design for Color Electrophoretic Display”, SID 2011 5.3 (hereinafter, simply “Yashiro”), and N. Hiji, “Novel Color Electrophoretic E-Paper Using Independently Movable Colored Particles”, SID 2012 8.4 (hereinafter, simply “Hiji”).
JP-A-2000-194021 discloses a display device in which a microcapsule includes a dispersion medium pigmented in black, and electrophoretic particles dispersed in the dispersion medium have different electrophoretic mobilities for different colors. This display device displays different tones in accordance with a difference in values of applied voltages or time periods of voltage application.
The specification of US-A1-2011/0310461 discloses an electrophoretic display device that displays a color image using red, green, blue, and white color filters.
The specification of US-A1-2006/0202949 discloses an electrophoretic display device in which a plurality of electrophoretic particles having different electrophoretic mobilities are included in a fluid. This electrophoretic display device displays an image in accordance with optical characteristics of the respective electrophoretic particles.
Yashiro discloses an electrophoretic display device that displays a color image using a configuration in which electrochromic layers are stacked on a per-color basis.
Hiji discloses an electrophoretic display device that displays a color image by independently controlling pigmented electrophoretic particles that have different thresholds.
As can be understood from JP-A-2000-194021, the specification of US-A1-2011/0310461, the specification of US-A1-2006/0202949, Yashiro, and Hiji, the characteristics of electrophoretic particles, as well as the characteristics of a liquid in which the electrophoretic particles are dispersed, are important elements in determining how an electrophoretic display device should be controlled. It is important for an electrophoretic display device to achieve further improvements in function, such as higher contrast, expansion in a temperature range of operation, extension in a time period for which a display state is retained, and reduction in a time period for which a display state is updated.